SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '81ec0e105801e4a0e788b5ae84dddd845b8967317631271ffc79737f6cf27b87' 
  AND token = 'Fh8y5OTrstqJbg0CpXPJQ+sMBLedWPPDOnYWcL71vzI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}